Source is 15.24 cm away from the left PMT
Source is 35.56 cm away from the left PMT
Source is 56.2 cm away from the left PMT
Source is 76.835cm away from the left PMT
Source is 87.31 cm away from the left PMT
Calibration curve
The slope is 0.129 ns/cm or 7.75 cm/ns.